Deduplication

Data Quality Patterns The most common use of window functions in production is cleaning and deduplicating data. These patterns form the foundation of reliable data pipelines. Dedup with ROW_NUMBER Funnel Analysis Funnel analysis tracks how users progress through a sequence of steps: signup, activation, first purchase, repeat purchase. The goal is to measure drop-off at each stage. Window functions enable ordered funnel tracking per user. This is one of the most requested analytics patterns in product companies, because it directly answers the question: "Where are we losing users?" Gap-and-Island Detection Which real-world pattern matches your analysis goal? Performance at Scale Production workloads require careful attention to memory usage and data distribution. These techniques keep windo